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Topic: The Light Leak Issue (Read 36920 times)

Perhaps, the LCD display needed to be lighted up to check the settings, but after it turns off automatically in a few seconds, then an exposure can be taken. There is no need for the LCD to be lighted up when an exposure is taken.

But what if you wanted to repeatedly verify your settings during the exposure by viewing the LCD during the exposure?!? Don't go saying that's not realistic because you can't change the settings at that point or that pressing a button on the camera would result in a blurry image. It's more realisitc than taking pictures with no lens...

LOL! Actually I don't even use the top LCD as I check all my settings in the rear LCD in quick mode all the time. I can't be bothered even if the top LCD is removed.

Canon EOS 60DI tested 2 bodies and found no issue once I placed the folded black fabric over the viewfinder. No change with backlight on.

Canon EOS 7DI tested 2 bodies and found no issue once I placed the folded black fabric over the viewfinder. No change with backlight on.

Canon EOS 5D Mark III tested the one body I have in stock. This camera exhibited the same issue as the 5D Mark III in direct sunlight, however the backlight didn’t affect exposure. I also did the flashlight test that is mentioned below and nothing changed in exposure.

Canon EOS-1D Mark IV – Body #1There was an ever so slight shift in exposure with the viewfinder cover down. 10 seconds out of the sun, 8 seconds in the sun. I stuffed the viewfinder with the black fabric and there was no change. The variance in exposure went away if I wrapped the LCD with the black fabric and only left enough space to see the exposure number. No change with backlight on.

Could someone check which side is the LED (inside the LCD) on all the tested bodies? In the 5D3, the LED is on the left side, closer to the metering sensor. Could it be that all the other bodies have the LED on the right side? Just a hyphothesis. You could check the LED position by looking sideways into the LCD.

I just did a similar test, taking two outdoor pictures with my new 5D MK iii. The one without the lcd light on is metered for 10" exposure duration and turns out fine. When I use the lcd backlight the meter shows 6" exposure duration and the shot gets underexposed by almost one 1 stop.I acknowledge these tripod mounted night shots with long exposure duration are not the ones I do regularly, but to me the light leak problem seems very real. So, should I send the camera back?

Is it normal practice (for you or anyone else for that matter) to have the LCD backlight on when metering? If your answer is no, then just use it as you normally would and don't waste your time and potentially money returning it. If yes, then may be you need to review your practices and/or make manual adjustments.

As I noted previously - some astrophotographers use the LCD backlight during metering to observe the exposure settings. Well - at least I do. This way I can use the settings to calculate a longer exposure for a manual/bulb exposure. And there's really no way to see that LCD display without activating the backlight (or by using a headlamp - which we're learning can also effect the metering).

So if we can't use the backlight under pitch black conditions out in the field - then one could certainly resort to the rear LCD image preview/info screen. However, this is a huge hindrance in my opinion. If the camera is on a tripod in a funky position, where access to the rear LCD is totally obstructed, you would literally be screwed.

I don't think everyone is realizing how much of a serious problem this is turning out to be (at least for nighttime landscape photographers).

Canon EOS 60DI tested 2 bodies and found no issue once I placed the folded black fabric over the viewfinder. No change with backlight on.

Canon EOS 7DI tested 2 bodies and found no issue once I placed the folded black fabric over the viewfinder. No change with backlight on.

Canon EOS 5D Mark III tested the one body I have in stock. This camera exhibited the same issue as the 5D Mark III in direct sunlight, however the backlight didn’t affect exposure. I also did the flashlight test that is mentioned below and nothing changed in exposure.

Canon EOS-1D Mark IV – Body #1There was an ever so slight shift in exposure with the viewfinder cover down. 10 seconds out of the sun, 8 seconds in the sun. I stuffed the viewfinder with the black fabric and there was no change. The variance in exposure went away if I wrapped the LCD with the black fabric and only left enough space to see the exposure number. No change with backlight on.

Could someone check which side is the LED (inside the LCD) on all the tested bodies? In the 5D3, the LED is on the left side, closer to the metering sensor. Could it be that all the other bodies have the LED on the right side? Just a hyphothesis. You could check the LED position by looking sideways into the LCD.

that was what i was suggesting. on my 7d the amber backlightled is on the right side.So it seems they made a placement error.It may be a small to nonexistent problem but still should be easy to fix for canon.

From the video previously posted by "highnfar," here are screen caps of images taken with the backlight on during metering, and backlight off during metering....

Yes, I agree I can see a visible difference between the images. But which image is the correct exposure for the scene and what you are trying to achieve? Without a review of the histograms and images, neither may be correct, and for night photography nor should they be assumed to be correct. (FWIW, the image on the right looks over-exposed, but its almost impossible to tell from such a small grab - and I do know the left is the LCD affected exposure.)I'm not saying there isn't a problem, there clearly is but it looks to be manageable. In my experimentation, I've found that the only time the exposure is affected is when the LCD panel in is brighter light than the image to be captured and how much it is affected depends on the intensity difference.With this knowledge in hand we are forewarned and hence forearmed and can work around it - albeit we shouldn't and I wish we didn't have to, but it is what it is at the moment. My workflow for night photography will not change:1. Compose the image and set focus.2. Set a high ISO, Aperture Priority, biggest aperture for the lens, set autobracket +/-1 stop.3. Review the 3 histograms and images.4. Switch to Manual mode, with same ISO, same aperture, and adjusted time based on review of previous images and the result I want to achieve.5. Confirm adjusted exposure by creating another image or adjust again. Determine Bulb exposure time for desired ISO and desired aperture.6. Set bulb setting, start exposure, grab a coffee, plug in the iPod and wait.

The good news is I've confirmed (on my 5D3 at least) that the light leakage does not get to the image sensor when the mirror is up, so the activation of the LCD or the use of a head-torch or similar during the exposure doesn't affect the image.

People are still screaming about this? Seriously? Yes yes, this is a HUGE PROBLEM!!!!!!!!!!!!IF you're doing near pitch-black landscape photographyAND you're relying on the meter to figure out your exposure for youAND you've put the camera in a place where you can't use the rear LCDAND you're not willing to wait to execute the exposure until after the LCD backlight turns off

I don't do much nighttime landscape / astrophotography - but when I have, I've never once relied on the camera's metering system. That's what M mode and a few test shots are for. Why all the drama?

Please could you check metering in normal use? I had very annoying problem with 5D2 which underexposed by 2/3 stop all the time. I did a white(gray) wall test with all different mattering modes and histogram against white or gray card was off to the left by 2/3 stop. it's not normal behaviour as it should be set dor 18% gray, so the histogram peak should be perfectly in center. Please check if 5d3 is also affected by this issue.

As often this forum is far too quick: there seem to be thousands of us doing every new hard/software test immediately and spreading the info minutes later: I find this is great! A company cannot compete with this speed especially if it is making non-vitally relevant products (no life danger from a light leak there). I expect weeks and months until we know if the cameras will be recalled and what will be done to them and where.

My 5D3 arrived on Friday and no one has phoned me over the weekend to let me know Canon needs it back on Monday. And, yes it has the light leak issue as my old 40D without me noticing.